Results of recent studies indicate that following microsurgical vasovasostomy sperm appears in the semen in approximately 85 to 97% of men.    From Wordnik.com.  [“Feminist and Pro-Life”; another reply to Hugo] Reference

This is in stark contrast to the traditional vasectomy, which cuts, sutures or cauterizes the vas deferens and, most importantly, Pro-Vas is reversible with a standard vasovasostomy procedure.    From Wordnik.com.  [THE MEDICAL NEWS] Reference